By Caitlin Ostroff

The S&P 500 wobbled Friday but remained on track to notch a big weekly gain, continuing its longest winning streak since October.

The broad stock market index rose about 0.1% early Friday after closing Thursday at its 19th all-time high for 2021. The benchmark is on track to notch gains for a third straight week for the first time in nearly six months. The Nasdaq Composite slipped 0.4%. The Dow Jones Industrial Average gained 114 points, or 0.3%.

The S&P 500 and Nasdaq are on track to gain about 2% a piece this week, while the Dow is on track for a 1.4% weekly rise.

Stocks surged this week, led by sharp gains for technology companies. Bond markets calmed, with yields dropping for four straight days before ticking higher on Friday. Investors are betting that economic growth will pick up as Covid-19 vaccines and government support help revitalize social and business activity. Federal Reserve officials also reiterated this week that the central bank will continue with policy measures aimed to support the recovery.

"It's been another week that's reminded us how addicted to policy support we are," said Georgina Taylor, a multiasset fund manager at Invesco. "Some of the comments out of the U.S. have cemented the market's view that policy can't shift any time soon, and that's put support behind the equity market."

In bond markets, the yield on the 10-year Treasury note ticked up to 1.673%, from 1.632% Thursday. It remains below the 1.749% it hit at the end of last month.

Some investors are cautioning that the pace of Covid-19 vaccinations and rising infection levels in some parts of the world may hobble the global recovery. Fed Chairman Jerome Powell on Thursday also said the sluggish pace of the vaccine-rollout outside the U.S. is a key threat to the outlook.

"We're going from this period of time where we're going 'whoa, everything is getting better' and we've forgotten there will be bumps on the road," said Lars Skovgaard Andersen, investment strategist at Danske Bank Wealth Management. "We are in for a time when we have much higher volatility."

Guidance on companies' future profits and sales prospects, which will be forthcoming when the quarterly earnings start next week, are also likely to determine the course of the market in coming weeks.

Overseas, the pan-continental Stoxx Europe 600 edged up 0.1%.

In Asia, most major benchmarks closed lower. The Shanghai Composite Index shed 0.9%, and Hong Kong's Hang Seng Index declined 1.1%. South Korea's Kospi edged down 0.4%.

Gunjan Banerji contributed to this article.

Write to Caitlin Ostroff at caitlin.ostroff@wsj.com

(END) Dow Jones Newswires

04-09-21 1019ET